by Kim Hjelmgaard, USA TODAY

by Kim Hjelmgaard, USA TODAY

LERWICK, Scotland - British Prime Minister David Cameron on Tuesday became the first prime minister in 34 years - since Margaret Thatcher in 1980 - to visit the remote Shetland islands. The surprise visit comes ahead of a referendum on Scottish independence.

Cameron's two-day visit to the area that sits more than 100 miles off the Scottish mainland and is closer to Oslo, Norway, than London is part of a drive to make his government's case that Scotland - all of Scotland, including its various clusters of distant islands - would be better off economically by remaining part of the United Kingdom.

The vote on Sept. 18 will decide whether Scotland opts to sever more 300 years of political union with England and Wales. Most polling projects the vote will fail.

"It's a bit late in the day this referendum," said Calum Ferguson, 35, an oil services worker who was relaxing Tuesday on the dock at Lerwick's quaint inner harbor.

"We sold our souls to the English a long time ago," he said, laughing.

Shetland has a population of just over 20,000 people, but the vast oil and gas reserves in the surrounding North Sea have brought prosperity to the islands in the form of pristine roads, well-funded schools and a disproportionate number of outstanding sports and leisure complexes.

Cameron has been aggressively campaigning for months to ensure that revenues from those reserves ultimately continue to flow to Britain's coffers rather than any new Scottish state ruled from Edinburgh. Scottish First Minister Alex Salmond has maintained that Scots would flourish by adopting a fully independent parliament and governing institutions, as well as rejecting the monarchy and other shared constitutional practices.

On Wednesday, the prime minister will travel to Glasgow to attend the opening ceremonies of the Commonwealth Games, which has participants from 71 countries and two territories.